Brent crude oil, seen as the best gauge of the global oil market, rose to an intra-day high of $78.40 a barrel, just below last August's all-time high of $78.65.

Profit-taking later pushed it back down to $77.32 a barrel.

Crude prices have risenby 51 per cent since hitting a year-low in January.

Goldman Sachs, the US bank, warned prices could surge to $95 a barrel within six months without increased production from the Organisation of the Petroleum Exporting Countries.

"Total crude oil supply is 1m barrels a day lower than last summer while demand is 1mb/d higher," the bank said in a report.

Opec again rejected calls to increase its supply, stating in its monthly report that the crude oil market was "healthy". The cartel, which controls about 40 per cent of global oil production, has so far rejected calls for a supply boost after having twice cut its output last year. It blames refinery bottlenecks for the rise in oil prices.

Analysts suggested further crude price rises were likely after new US figures showed levels of speculative money betting on rising prices last week reached a record high.

However, some traders warned that before any movement higher the market was vulnerable to a correction in the short term, especially if the forecast of an active hurricane season proved overstated.

Rising energy costs have prompted policymakers to warn about a possible inflationary impact, just days after the International Energy Agency, the industrialised countries' energy watchdog, reiterated its callon Opec to increase its production.